Printed circuit board features of a portable computer

ABSTRACT

Tools and fixtures for assembling a printed circuit board (PCB), such as a main logic board (MLB), in a portable computer device are described. A connector assembly having an electrically conductive gasket mounted on an edge of the MLB is described. In addition, a keyboard assembly including a notched portion of the MLB for accommodating more than one type of keyboard is described. In addition, a PCB assembly having a bracket to support a weak region of the PCB during assembly is described.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of co-pending commonly assigned U.S.patent application Ser. No. 13/855,681 filed Apr. 2, 2013 entitled“Printed Circuit Board Features of a Portable Computer”, which claimspriority under 35 USC 119(e) to U.S. Provisional Patent Application No.61/795,542 filed Oct. 18, 2012 entitled “Printed Circuit Board Featuresof a Portable Computer” by Smith et al. which is incorporated byreference in its entirety for all purposes.

FIELD OF THE DESCRIBED EMBODIMENTS

The described embodiments relate generally to portable computingdevices. More specifically, the present embodiments relate to variousfeatures of printed circuit boards (PCBs), such as the main logic board(MLB), of the portable computing device. Methods include the use offixtures during the assembly of PCBs in the portable computing devices.

BACKGROUND

The assembly of computer devices involves the positioning of manydifferent components within regions of the housings of the computerdevices. The positioning of the components in relation to each other isan important design consideration to assure that the components canadequately communicate with each other and not interfere with each otherduring operation of the computer. For portable computers in particular,it is also important that the components are securely fixed within thehousings to withstand any jostling and vibrations associated withordinary use.

The main logic board (MLB), which is the main circuit board of aportable computer, typically contains the central processing unit andmain system memory as well as circuitry that controls the disk drives,keyboard, monitor, and other peripheral devices. Because of its centralrole, it is important that the MLB be positioned within the housing suchthat other components can adequately communicate with the MLB. It isalso important that the MLB be adequately secured and protected to avoiddamage to the MLB during and after assembly of the portable computer.

SUMMARY

This paper describes various embodiments that relate to features relatedto printed circuit boards (PCBs) such as the main logic board (MLB) of aportable computing device. Methods, fixtures and devices used forassembling an MLB in a portable computer device are described.

According to one embodiment described herein, a connector assemblyhaving an electrically conductive gasket is mounted on an edge of theMLB is described. The connector assembly includes a receptacleconfigured to accept a connector, the connector being configured toconnect to and communicate with an external electronic device. Theconnector assembly also includes an opening formed in a housing of theportable computing device, the opening being configured to conform tothe receptacle. The connector assembly further includes an electricallyconductive gasket. The electrically conductive gasket can have anelongated portion configured to provide mechanical and electricalcontact with a portion of the housing of the portable computing device,and at least one finger portion that is mechanically and electricallycoupled to the elongated portion. The at least one finger portion can beelectrically coupled to the receptacle such that a ground path is formedbetween the external electronic device and the housing of the portablecomputing device via the electrically conductive gasket.

According to another embodiment, a keyboard assembly including a notchedportion of the MLB is described. The keyboard assembly includes a firstweb having a first support structure and a number of first openingsconfigured to accept a set of first keys. The first support structurecan have a first boss configured to accept a first fastener. Thekeyboard assembly also includes a main logic board configured to acceptinput from the set of first keys. The MLB has a notch corresponding tothe first boss and is configured to accept the first fastener. The notchhas a suitable size and shape to correspond to a second boss of a secondweb and configured to accept the second fastener. In this way, a singleMLB design having a universal notch can be used for assembly with morethan one type of keyboard layout (e.g., ANSI, JIS or ISO keyboardlayouts).

According to another embodiment, a printed circuit board (PCB) assemblyhaving a bracket to support a weak region of the PCB during assembly isdescribed. The PCB can be part of the MLB of the portable computingdevice. The PCB assembly includes a base having a number of attachmentfeatures for attaching a number of components to the base. The base hasa cut out having the size and shape to accept a part therein. Because ofthe cut out, the base has a mechanically weak region which canexperience mechanical strain during handling when the cut out is empty.The PCB assembly also includes a bracket having a size an shapecorresponding to the cut out, wherein the mechanically weak region canexperience less mechanical strain when the bracket is positioned in thecut out and attached to the base compared to when the cut out is empty.Methods for assembling a PCB in a portable computing device aredescribed. Methods can include first receiving a PCB having a base and anumber of attachment features for attaching a number of components tothe base. The cut out of the base can have the size and shape to accepta part therein, wherein the base has a mechanically weak region whichcan experience mechanical strain during handling when the cut out isempty. Next, a PCB assembly is formed by mounting a bracket in the cutout, the bracket having a size and shape corresponding to the cut out.As a result, the mechanically weak region can experience less mechanicalstrain when the bracket is positioned in the cut out and attached to thebase compared to when the cut out is empty. Next, the PCB assembly isassembled in the portable computing device. Next, the bracket is removedfrom the cut out of the printed circuit board. Finally, the part ismounted in the cut out of the PCB.

According to another embodiment, a method for shielding an antenna cablesituated on the MLB is described. Methods can include first receiving aPCB having: a base configured to accept a number of components; a radiocard mounted on the base, the radio card having at least one connectorfor attaching an antenna cable thereto, where the radio card isconfigured to process radio signals received and/or transmitted from/toan antenna via the antenna cable; and a high-definition multimediainterface (HDMI) receptacle positioned at the edge of the base, wherethe HDMI receptacle is configured to connect to and communicate with acorresponding HDMI connector for an external device. Next, a shield ismounted on the base between the radio card and the HDMI receptacle,where the shield reduces the electromagnetic noise experienced by theradio card and the antenna cable generated by HDMI receptacle. Finallyand a separator is disposed on at least a portion of the surface of theshield, where the separator reduces electromagnetic noise experienced bythe antenna cable emitted from the shield by providing a distance gapbetween the antenna cable and the shield.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments will be readily understood by the following detaileddescription in conjunction with the accompanying drawings with likereference numerals designating like structural elements, and in which:

FIG. 1 shows a front facing perspective view of an embodiment of aportable computing device in an open (lid) state.

FIG. 2 shows the portable computing device of FIG. 1 in a closed (lid)state that shows rear cover and logo.

FIG. 3 shows an external view of bottom case of the portable computingdevice of FIGS. 1 and 2.

FIG. 4 illustrates a top view of an interior portion of a portablecomputing device having a double stack gasket as part of a connectorassembly.

FIG. 5 illustrates a perspective view of the connector assembly of FIG.4.

FIG. 6 illustrates a cross section view of the connector assembly ofFIGS. 4 and 5.

FIG. 7 illustrates a different cross section view of the connectorassembly of FIGS. 4-6.

FIG. 8 illustrates a bottom-up view of top case of a portable computingdevice showing an integrated support system.

FIGS. 9A and 9B illustrate bottom-up views of portions of a keyboard weband main logic board assemblies.

FIGS. 10A and 10B illustrate bottom-up views of portions of keyboardassemblies showing a PCB notch to accommodate different keyboardlayouts.

FIGS. 11A-11D illustrate different PCB notch shapes in accordance withdescribed embodiments.

FIG. 12 illustrates a top-down view of a portion of an MLB of a portablecomputing device showing a cut out in the PCB.

FIGS. 13A and 13B illustrate top-down and isometric view, respectively,of the MLB of FIG. 12 with a fan installed in the cut out of the PCB.

FIGS. 14A and 14B illustrate top-down and isometric view, respectively,of the MLB of FIG. 12 with a bracket installed the cut out of the PCB.

FIG. 15 is a flowchart showing process steps for assembling a PCB havingbracket in a portable computing device.

FIG. 16A illustrates a top-down view of a portion of a MLB having aradio card, antenna cables, a high-definition multimedia interface and ashield.

FIGS. 16B and 16C illustrate top-down and isometric views, respectively,of the MLB of FIG. 16A having a separator mounted on the shield.

FIG. 17 is a flowchart showing process steps for shielding an antennacable of a portable computing device.

DETAILED DESCRIPTION OF SELECTED EMBODIMENTS

The following disclosure describes various embodiments of featureswithin a portable computing device. Certain details are set forth in thefollowing description and Figures to provide a thorough understanding ofvarious embodiments of the present technology. Moreover, variousfeatures, structures, and/or characteristics of the present technologycan be combined in other suitable structures and environments. In otherinstances, well-known structures, materials, operations, and/or systemsare not shown or described in detail in the following disclosure toavoid unnecessarily obscuring the description of the various embodimentsof the technology. Those of ordinary skill in the art will recognize,however, that the present technology can be practiced without one ormore of the details set forth herein, or with other structures, methodsand components.

Representative applications of methods and apparatuses according to thepresent application are described in this section. These examples arebeing provided solely to add context and aid in the understanding of thedescribed embodiments. It will thus be apparent to one skilled in theart that the described embodiments may be practiced without some or allof these specific details. In other instances, well known process stepshave not been described in detail in order to avoid unnecessarilyobscuring the described embodiments. Other applications are possible,such that the following examples should not be taken as limiting.

In the following detailed description, references are made to theaccompanying drawings, which form a part of the description and in whichare shown, by way of illustration, specific embodiments in accordancewith the described embodiments. Although these embodiments are describedin sufficient detail to enable one skilled in the art to practice thedescribed embodiments, it is understood that these examples are notlimiting, such that other embodiments may be used, and changes may bemade without departing from the spirit and scope of the describedembodiments.

The following describes methods and tools used for assembling a portablecomputing device. In particular, features of a main logic board (MLB) ofa portable computing device are described. In general, the main logicboard, sometimes referred to as the motherboard, is the main circuitboard of a computer, usually containing the central processing unit andmain system memory as well as circuitry and components for controllingdisk drives, keyboard, monitor and other peripheral devices. The printedcircuit board (PCB) of the MLB typically has a non-conductive base orsubstrate that has components mounted thereon and electricallyconductive pathways laminated on the base to connect the variouscomponents. The embodiments described herein involve improved featuresof an MLB of a portable computing device. Some features can aid in theassembly of the MLB in the housing of the portable computing device.Other features provide ways to adequately secure the MLB inside thehousing of the MLB. Other features can help improve the performance ofcomponents on the MLB.

These and other embodiments are discussed below with reference to FIGS.1-17. However, those skilled in the art will readily appreciate that thedetailed description given herein with respect to these figures is forexplanatory purposes as the invention extends beyond these limitedembodiments.

The portable computing device can include a multi-part housing having atop case and bottom case joined together to form a base portion. Theportable computing device can have an upper portion (or lid) that canhouse a display screen and other related components. The base portioncan house processors, drives, ports, a battery, a keyboard, a touch pad,etc. The upper portion can be pivotally connected to the bottom portionusing clutch hinge assembly. The housing can be formed of a strong anddurable yet lightweight material. Such materials can include compositematerials or metals such as aluminum. Since aluminum is a goodelectrical conductor, a housing formed of aluminum can act as a chassisground for internal electrical components arranged to fit and operatewithin the housing.

FIGS. 1-17 show various views of a portable computing device inaccordance with various embodiments. FIG. 1 shows a front facingperspective view of an embodiment of a portable computing device in theform of portable computing device 100 in an open (lid) state. Portablecomputing device 100 can include base portion 102 formed of bottom case104 fastened to top case 106. Base portion 102 can be pivotallyconnected to lid portion 108 by way of clutch assembly 110 hidden fromview by a cosmetic wall. Base portion 102 can have an overall uniformshape sized to accommodate clutch assembly 110 and inset portion 112suitable for assisting a user in lifting lid portion 108 by, forexample, a finger. Top case 106 can be configured to accommodate varioususer input devices such as keyboard 114 and touchpad 116. Keyboard 114can include a plurality of low profile keycap assemblies each having anassociated key pad 118. The main logic board (MLB) (not shown) ispositioned partially under keyboard 114 of portable computing device100. In one embodiment, an audio transducer (not shown) can use selectedportions of keyboard 114 to output audio signals such as music. In thedescribed embodiment, a microphone can be located at a side portion oftop case 106 that can be spaced apart to improve frequency response ofan associated audio circuit.

Each of the plurality of key pads 118 can have a symbol imprintedthereon for identifying the key input associated with the particular keypad. Keyboard 114 can be arranged to receive a discrete input at eachkeypad using a finger motion referred to as a keystroke. In thedescribed embodiment, the symbols on each key pad can be laser etchedthereby creating an extremely clean and durable imprint that will notfade under the constant application of keystrokes over the life ofportable computing device 100. In order to reduce component count, akeycap assembly can be re-provisioned as a power button. For example,key pad 118-1 can be used as power button 118-1. In this way, theoverall number of components in portable computing device 100 can becommensurably reduced.

Touch pad 116 can be configured to receive finger gesturing. A fingergesture can include touch events from more than one finger applied inunison. The gesture can also include a single finger touch event such asa swipe or a tap. The gesture can be sensed by a sensing circuit intouch pad 116 and converted to electrical signals that are passed to aprocessing unit for evaluation. In this way, portable computing device100 can be at least partially controlled by touch.

Lid portion 108 can be moved with the aid of clutch assembly 110 fromthe closed position to remain in the open position and back again. Lidportion 108 can include display 120 and rear cover 122 that can add acosmetic finish to lid portion 108 and also provide structural supportto at least display 120. In the described embodiment, lid portion 108can include mask (also referred to as display trim) 124 that surroundsdisplay 120. Display trim 124 can be formed of an opaque material suchas ink deposited on top of or within a protective layer of display 120.Display trim 124 can enhance the overall appearance of display 120 byhiding operational and structural components as well as focusingattention onto the active area of display 120.

Display 120 can display visual content such as a graphical userinterface, still images such as photos as well as video media items suchas movies. Display 120 can display images using any appropriatetechnology such as a liquid crystal display (LCD), OLED, etc. Portablecomputing device 100 can also include image capture device 126 locatedon a transparent portion of display trim 124. Image capture device 126can be configured to capture both still and video images. Lid portion108 can be formed to have uni-body construction that can provideadditional strength and resiliency to lid portion 108 which isparticularly important due to the stresses caused by repeated openingand closing. In addition to the increase in strength and resiliency, theuni-body construction of lid portion 108 can reduce overall part countby eliminating separate support features.

Data ports 128-132 can be used to transfer data and/or power between anexternal circuit(s) and portable computing device 100. Data ports128-132 can include, for example, input slot 132 that can be used toaccept a memory card (such as a FLASH memory card), data ports 128 and130 can take be used to accommodate data connections such as USB,FireWire, Thunderbolt, and so on. In some embodiments, an audio portembodied as part of keyboard 114 is used to port audio from anassociated audio component enclosed within base portion 102.

FIG. 2 shows portable computing device 100 in a closed (lid)configuration that shows rear cover 122 and logo 202. In one embodiment,logo 202 can be illuminated by light from display 120. It should benoted that in the closed configuration, lid portion 108 and base portion102 form what appears to be a uniform structure having a continuouslyvarying and coherent shape that enhances both the look and feel ofportable computing device 100.

FIG. 3 shows an external view of bottom case 104 showing relativepositioning of support feet 302, insert 112, cosmetic wall 304 that canbe used to conceal clutch assembly 110 and fasteners 306 used to securebottom case 104 and top case 106 together. Support feet 302 can beformed of wear resistant and resilient material such as plastic. Also inview are multi-purpose front side sequentially placed vents 308 and 310that can be used to provide a flow of outside air that can be used tocool internal components. In the described embodiment, vents 308 and 310can be placed on an underside of top cover 106 in order to hide thevents from view as well as obscure the view of an interior of portablecomputing device 100 from the outside. Vents 308 and 310 can act as asecondary air intake subordinate to primary air intake vents located ata rear portion of portable computing device 100 (described below). Inthis way, vents 308 and 310 can help to maintain an adequate supply ofcool air in those situations where portions of the rear vents areblocked or otherwise have their air intake restricted.

Vents 308 and 310 can also be used to output audio signals in the formof sound generated by an audio module (not shown). In one embodiment, aselected portion (such as portions 312 and 314) can be used to outputsound at a selected frequency range in order to improve quality of anaudio presentation by portable computing device 100. Vents 308 and 310can be part of an integrated support system in that vents 308 and 310can be machined from the outside and cut from the inside duringfabrication of top case 106. As part of the machining of vents 308 and310, stiffener ribs 316 can be placed within vent openings 308 and 310to provide additional structural support for portable computing device100. Stiffener ribs 416 can be formed using what is referred to as a Tcutter that removes material subsequent to the formation of the ventopenings during the fabrication of top case 106.

Moreover, trusses 318 can be formed between vents 308 and 310 incombination with ribs 316 can add both structural support as well asassist in defining both the cadence and size of vents 308 and 310. Thecadence and size of vents 308 and 310 can be used to control air flowinto portable computing device 100 as well as emission of RF (radiofrequency) energy in the form of EMI from portable computing device 100.Accordingly, stiffener ribs 316 can separate an area within vents 308and 310 to produce an aperture sized to prevent passage of RF energy. Asknown from electromagnetic theory, the size of an aperture can restrictthe emission of RF energy having a wavelength that can be “trapped” bythe aperture. In this case, the size of vents 308 and 310 is such that asubstantial portion of RF energy emitted by internal components can betrapped within portable computing device 100. Furthermore, by placingvents 308 and 310 at a downward facing surface of top case 106, theaesthetics of portable computing device 100 can be enhanced since viewsof internal components from an external observer are eliminated.

During assembly of the portable computing device 100 shown in FIGS. 1-3,the MLB is positioned inside base portion 102 such that components of onthe MLB can communicate with each other, with other components of theportable computing device 100 or peripheral components. Various featuresinvolving the MLB of portable computing device 100 will be describedbelow with reference to FIGS. 4-17, which illustrate various internalportions of portable computing device 100 during assembly processes.

Double Stack Gasket for Port Receptacles

As described above with reference to FIGS. 1-3, data ports 128-132 canbe used to transfer data and/or power between portable computing device100 and external devices. Data ports 128-132 allow for communicationbetween external devices and the MLB of portable computing device 100.The ports have receptacles that are configured to accommodatecorresponding external connectors. The receptacles can accommodate, forexample, USB, FireWire and Thunderbolt connectors. If the housing of theportable computer device is made of an electrically conductive materialsuch as aluminum, the portions of the receptacles can be electricallycoupled to the housing to provide an electrical ground for theconnecting device. FIGS. 4 and 5 show close up top and perspective viewsof interior portions of portable computing device 100 illustrating adouble stack gasket 400 as part of a connector assembly. Externaldevices can be connected to the computer device via openings 406.Openings 406 are formed in upper case 408 of the housing of the portablecomputing device. As shown, openings 406 are configured to acceptcorresponding dual Thunderbolt connectors. In other embodiments,openings 406 are configured for accepting USB, serial and FireWireconnectors, or other suitable connectors. Double stack gasket 400, whichis electrically conductive, includes finger portions 404 and anelongated portion 402. It should be noted that finger portions 404 andelongated portion 402 can have any shapes, including a rectangularsurfaces with straight edges. In addition, the double stack gasket canhave any suitable number of finger portions 404 connected by anelongated portion 402. In some embodiments, double stack gasket 400 ismade of a flexible and conductive foam material, such as a silicon foammaterial embedded with conductive particles. In one embodiment, theconductive particles include silver particles. In some embodiments,double stack gasket 400 is made of a single piece of conductive siliconmaterial which is sculpted using, for example, die cuts to create thestep or finger portions 404. In other embodiments, double stack gasket400 is fabricated by adhering separate finger portions 404 to elongatedportion 402 using, for example, a conductive adhesive.

FIGS. 6 and 7 show cross section views of a connector assembly having adouble stack gasket 400. Openings 406 are configured to substantiallyconform to receptacles 418. Receptacles 418 are configured to accept aconnector 420, which is in turn configured to connect to an externaldevice (not shown). Shield 412 surrounds receptacles 418 and isconfigured to make physical and electrical contact with portions of aconnector of an external device. Shield 412 includes spring fingers 410which can physically and electrically contact upper case 408 of thehousing, thereby providing a low impedance conductive pathway to groundat upper case 408. Finger portions 404 can physically and electricallycouple with metal shield 412 at interface 414. Finger portions 404 canbe affixed to metal shield 412 using a conductive adhesive material. Asshown in FIG. 7, when the portable computer is assembled, elongatedportion 402 can make physical and electrical contact with bottom case416. In addition, finger portions 404 can make physical and electricalcontact with ground sheath 422 of connector 420. In some embodiments,bottom case 416 is anodized with a portion that is laser etched toprovide a conductive contact for elongated portion 402. In this way, aground path is formed between the external electronic device and thebottom case via the double stack gasket 400. In addition, from theperspective of a user who opens the bottoms case 416 to, for examplerepair the portable computer, the user will see elongated portion 402 ofdouble stack gasket 400, which can be more cosmetically appealingcompared to viewing individual finger portions 404.

MLB Features for Accommodating Regional Keyboards

As described above, portable computing device 100 of FIGS. 1-3 has abase portion 12 which includes bottom case 104 and top case 106. Topcase 106 has an integrated support system for supporting differentstructures of the computing device 100. FIG. 8 shows a bottom-up view ofa top case 106 showing integrated support system 800 in accordance withthe described embodiments. Generally speaking, top case 106 can bedivided into various structural zones each of which can be expected toexperience varying amounts and types of externally applied loads. Forexample, top case 106 can include palm rest zone 802 that can beexpected to experience an external load applied by a user resting a palmor hand on top case 106 in the vicinity of palm rest zone 802. Keyboardzone 812 can include keyboard support rib 814 that surrounds and definesa keyboard opening in keyboard zone 812. Keyboard zone 812, which canalso be referred to as a web, has a support structure 820 which hasopenings 816 formed therein to accommodate a keyboard positioned behindweb 812. Web 812 is expected to experience an external load applied by auser during typing. Other structural zones can include touch pad zone804, side vents zone 806, rear vent zone 808 and clutch bolt zone 810each of which can be expected to experience varying amount and types ofexternally applied loads. Accordingly, integrated support system 800 canbe configured in such a way to take into account the load expected ateach of the structural zones.

Structural support system 800 can provide support elements (such asbosses) that can be used to mount internal components to top case 106.For example, web 812 has bosses 818 to which fasteners or stand-offs canbe used to attach the MLB. Different geographical regions requiredifferent keyboard layouts. For example, Japan uses a JapaneseIndustrial Standard (JIS) keyboard layout, European countries use anInternational Standards Organization (ISO) keyboard layout and theUnited States uses an American National Standards Institute (ANSI)keyboard layout. Thus, web 812 can have different keyboard openingdesigns to accommodate different keyboard layouts depending on where aparticular device is being sold.

To illustrate, FIGS. 9A and 9B illustrate bottom-up views of portions ofweb and MLB assemblies with webs configured to accommodate ANSI and JISkeyboards, respectively. In FIG. 9A, assembly 900 includes ANSI web 902having openings 904 to accommodate an ANSI keyboard (not shown). ANSIweb 902 has boss 906 configured to accept a fastener or stand-off tocouple web 902 to MLB 908. MLB 908 is partially positioned in front ofweb 902. MLB 908 has aperture 910, which is aligned with boss 906 of web902, to accept the fastener or stand-off and to couple MLB 908 to web902. In FIG. 9B, assembly 920 includes a JIS web 922 having openings 924to accommodate a JIS keyboard (not shown). As shown, openings 924 of JISweb 922 are shifted in relation to openings 904 of ANSI web 902. JIS web922 has boss 926 configured to accept a fastener or stand-off to coupleweb 922 to MLB 928. MLB 928 is positioned partially in front of web 922.MLB 928 has aperture 930, which is aligned with boss 926 of web 922, toaccept the fastener or stand-off and to couple MLB 928 to web 922. Asshown, in order to align with boss 926, part of aperture 930 ispositioned off of an edge of MLB 928. When a fastener is used to coupleMLB 928 to JIS web 922 via aperture 930 and boss 926, MLB 928 may not beadequately secured to web 922. In some cases, MLB 928 can fall off thefastener and decouple from web 922.

The embodiments herein provide features on an MLB in order toaccommodate different types of keyboard layouts using a single design.FIGS. 10A and 10B illustrate bottom-up views of portions of keyboardassemblies which include one type of MLB that is adapted to accommodatedifferent webs having different keyboard layouts. FIG. 10A shows an ANSIweb 1002 with a support structure 1004 having a number of openings 1006configured to accept an ANSI keyboard. MLB 1010 is positioned in frontof ANSI web 1002. As shown in the inset view, ANSI web 1002 has boss1008 which is configured to accept a fastener or stand-off forsupporting MLB 1010. MLB 1010 has notch 1012 which includes a firstportion 1014 and a second portion 1016, each configured to accept afastener such as a screw. First portion 1014 is substantially circularin shape and second portion 1016 is at an edge of MLB. Second portion1016 is aligned with boss 1008 of ANSI web 1002 such that a fastener orstand-off can be positioned there through to securely fasten MLB 1010 toANSI web 1002. In some embodiments, gripping feature 1018 is provided,which can include a high friction surface to provide extra support forthe fastener. Gripping feature 1018 can be, for example, a texturedportion of the MLB produced, for example, by etching the MLB.Alternatively, gripping feature 1018 can be a compressible material suchas silicone or rubber that is affixed to or not affixed to MLB 1010.

FIG. 10B shows a JIS web 1022 with a support structure 1024 having anumber of openings 1026 configured to accept a JIS keyboard. MLB 1010 ispositioned partially in front of JIS web 1022. Note that MLB 1010 canalso be used with an ANSI web as shown in FIG. 10A. As shown in theinset view, JIS web 1022 has boss 1028 which is configured to accept afastener or stand-off for supporting MLB 1010. MLB 1010 has notch 1018which includes a first portion 1014 and a second portion 1016, eachconfigured to accept a fastener such as a screw. First portion 1014 isaligned with boss 1028 of JIS web 1022 such that a fastener or stand-offcan be positioned there through to securely fasten MLB 1010 to JIS web1022. As with the ANSI web, in some embodiments, gripping feature 1018is used to provide a high friction surface for extra support for thefastener. Thus, as shown by FIGS. 10A and 10B, MLB 1010 can be used forboth ANSI and JIS webs. In some embodiments, the MLB can have a notchthat can accommodate three or more types of webs, such as webs toaccommodate ISO and other keyboard configurations.

FIGS. 11A-11D illustrate different notch shapes for an MLB toaccommodate different types of keyboards in accordance with describedembodiments. FIG. 11A shows notch 1100 having a substantially circularfirst portion 1102 and second portion 1104 shaped to fit a fastener andpositioned at the edge of the MLB. FIG. 11B shows notch 1106 havingsubstantially circular first 1108 and second portions 1110. FIG. 11Cshows notch 1112 with first 1114 and second 1116 portions togetherforming a substantially oval shape. FIG. 11D shows notch 1118 with first1120 and second 1122 portions together forming a substantially ovalshape and second portion 1122 having tapered regions 1124 next to theedge of the MLB.

MLB Thin Section Support

As described above the MLB can play a central role in the functioning ofportable computing device 100. As such, it is important that the MLB beprotected from damage that can occur during assembly of the portablecomputing device. FIG. 12 illustrates top-down view of a portion of abare printed circuit board (PCB) 1200 of an MLB in accordance withdescribed embodiments. PCB 1200 can have features for mounting a numberof components as part of the MLB. The base of PCB 1200 is generally madeof an insulating material such as a resinous material. As shown, PCB1200 has a cut out 1202 for accommodating a fan or blower (not shown)for cooling the portable computing device. The fan or blower can becoupled to PCB 1200 using fasteners to fasten PCB 1200 to the fan orblower via openings 1204. As shown, PCB 1200 has a thin section 1206where PCB 1200 has a small length relative to a wider section of PBC 120having a maximum length 1208. In some embodiments, the thickness of PCBis about 1 mm and thin section 1206 is about 11-12 mm in length. Becauseof its relative thinness, PCB 1200 at thin section 1206 can subject tomechanical strain during assembly of the portable computing device andcan thus be considered a mechanically weak region of PCB 1200. Ifcomponents, such as integrated chips, and/or connectors are alreadyassembled on PCB 1200, bending or twisting of PBC 1200 at thin section1206 can cause damage to the components and/or wires near thin section1206. Bending or twisting at thin section 1206 can occur, for example,when PCB is being assembled into the housing of the portable computingdevice.

FIGS. 13A and 13B illustrate top-down and isometric views of assembly1300 which includes PCB 1200 and fan 1302 assembled in cut out 1202. Asshown, fasteners 1304 are used to secure fan 1302 to PCB 1200. When fan1302 is positioned in cut out 1202 and attached to PCB 1200, thinsection 1206 is adequately supported. In some embodiments, fan 1302 isnot assembled onto PCB 1200 until after PCB 1200 is assembled in thehousing of the portable computing device, thereby leaving thin section1206, and nearby components, vulnerable to damage from handling.

In accordance with described embodiments, a bracket can be positioned incut out 1202 in order to mechanically support thin section 1206 frommechanical strain. FIGS. 14A and 14B illustrate top-down and isometricviews of assembly 1400 which includes PCB 1200 and bracket 1402assembled in cut out 1202. As shown, bracket 1402 is configured to havethe size and shape corresponding to cut out 1202 so that bracket can bepositioned in cut out 1202 and attached to PCB 1200 using fasteners1304. Note that bracket 1402 is configured to have attachment features1404 positioned such that fasteners 1304 can be used to secure bracket1402 to PCB 1200 via corresponding openings 1204, which are the sameopenings 1204 used to attach fan 1302 to PCB 1200. Any suitablefasteners can be used, for example, screws, bolts, clips, snappingfeatures, spring clamps and/or magnets can be used. By mounting bracket1402 in cut out 1204, thin section 1206 can experience less mechanicalstrain during handling compared to when cut out 1204 is empty, as shownin FIG. 12. Bracket 1402 can be made of any suitable material capable ofsupporting thin section 1206. For example, bracket 1402 can be made ofsheet metal, durable plastic material or resinous material similar tothe base of PCB 1200. In some embodiments, bracket 1402 can have bendedportions 1406 that protrude substantially perpendicularly from at asurface of bracket 1402. Bended portions 1406 can be used as stops toalign PCB 1200 to a reference surface (e.g., corresponding stopsattached to the housing) to assure proper alignment of PCB 2100 duringassembly of PCB 1200 in the portable computer device. In addition,bended portions can be used as handles such that a handler can mount andremove bracket 1402 to/from PCB 1200 more easily. Bracket 1402 can bemounted in PCB 1200 prior to any operation involving handing such asmounting components onto PCB 1200 and assembling PCB 1200 in the housingof the portable computing device.

FIG. 15 is a flowchart 1500 showing process steps of an embodiment forassembling a PCB in a portable computing device. At 1502, a PCB having abase with a cut out for a part and a mechanically weak region, asdescribed above, is received. The cut out can have a size and shape toaccept a part therein. The part can be any suitable part mounted on aPCB. In some embodiments, the part is a fan or blower to keep theportable computing device cool during operation. The mechanically weakregion can be a thin section of the base that can experience mechanicalstrain during handling of the PCB when the cut out is empty. That is,the mechanically weak region can have reduced dimensions relative toother portions of the base. At 1504, a PCB assembly is formed bymounting a bracket in the cut out. The bracket can have a size and shapecorresponding to the cut out. When the bracket is mounted in the cutout, the mechanically weak region can experience less mechanical straincompared to when the cut out is empty. Note that in some embodiments,components can be mounted before or after the bracket is mounted in thecut out. At 1506, the PCB assembly is assembled in the portablecomputing device. During assembly into portable computing device, thePCB assembly can be subject to handling. Since the bracket is mounted inthe PCB, the weak region can be adequately supported to avoid mechanicalstrain to the weak region and any surrounding components or cables. At1508, the bracket is removed from the cut out. Thus, the bracket is atemporary structure that provides support for the PCB during assemblybefore the part is installed. At 1510, the part is mounted in the cutout of the PCB. It should be noted that the bracket can be reused insupporting a PCB during the assembly of another PCB in another portablecomputing device.

Antenna Cable Shield and Separator

Referring again to FIG. 1, portable computing device 100 can have anumber of antennas, such as WiFi, 3G and/or Bluetooth antennas, fortransmitting and/or receiving electromagnetic frequencies duringoperation of portable computing device 100. The antennas can besensitive to the noise floor of portable computing device 100. Ingeneral, the noise floor is the measure of the signal power created fromthe sum of the electromagnetic noise sources and unwanted signals withina measurement system, where noise is defined as any signal other thanthe one being monitored. In portable computing device 100, the noisefloor can include electromagnetic noise emitted from components andconnectors on the MLB, which can reduce the sensitivities of theantennas that are in proximity to such components and connectors.

FIG. 16A illustrates a top-down view of a portion of MLB 1600 that canbe part of portable computing device 100. MLB 1600 has mounted thereonradio card 1602 having connectors 1604 and antenna cables 1606. Antennacables 1606 are, in turn, connected to an antenna (not shown). Radiocard 1602 can process radio signals received and/or transmitted from/toantenna via antenna cables 1606. High-definition multimedia interface(HDMI) receptacle 1608 is positioned at an edge of MLB 1600 and isconfigured to connect to and communicate with a corresponding HDMIconnector for an external device. Shield 1610 is positioned betweenradio card 1602 and HDMI receptacle 1608 and is used to reduce theelectromagnetic noise generated by HDMI receptacle 1608 that can beexperienced by radio card 1602. Shield 1610 can be made of suitablematerial such as sheet metal. Although shield 1610 can reduce the amountof noise generated by HDMI receptacle 1608 experienced by radio card1602 and antenna cables 1606, shield 1610 can itself emitelectromagnetic noise due to its proximity to HDMI receptacle 1608.Since antenna cables 1606 are positioned on top of shield 1610, antennacables 1606 can experience noise emitted from shield 1610. Methodsdescribed herein are used to reduce the electromagnetic noise generatedby shield 1610 and maximize the sensitivity of the antenna to wirelesssignals.

FIGS. 16B and 16C illustrate top-down and cross-section perspectiveviews, respectively, of a portion of MLB 1600 with a separator 1612positioned on top of shield 1610. In some embodiments, separator 1612 ispositioned over a portion of shield 1610. Separator 1612 can be made ofany suitable insulator material such as a polymer material (e.g., Mylar)or a durable plastic material. Separator 1612 can also be made of an RFabsorbing material which can further reduce the radio frequency noiseexperienced by the antenna cable. In some embodiments, the choice ofmaterial for separator 1612 can partially be made based on the cosmeticreasons. For example, the color of separator 1612 can be chosen to matchthe color of nearby components housed within the portable computingdevice. Separator 1612 provides a distance gap between antenna cables1606 and shield 1610 and can reduce electromagnetic noise that antennacables 1606 can experience from emitted from shield 1610. In someembodiments, separator 1612 can be less than 1 mm in thickness. Incertain embodiments, separator 1612 can have features to affix or snapon antenna cables 1604 to separator 1612 in order to secure and preventmovement of antenna cables 1604. Separator 1612 can be secured on shieldusing, for example, an adhesive. In some cases, separator 1612 has bendportions so that it can couple with side portions of shield 1610.

FIG. 17 is a flowchart 1700 showing process steps of an embodiment forshielding an antenna cable of a portable computing device. At 1702, aprinted circuit board having a base with a radio card and an HDMIreceptacle mounted on the base is provided. The radio card can have atleast one connector for attaching an antenna cable thereto. The HDMIreceptacle is positioned at the edge of the base. At 1704, a shield ismounted on the base between the radio card and the HDMI receptacle. Asdescribed above, the shield can reduce the electromagnetic noiseexperienced by the radio card and the antenna cable generated by HDMIreceptacle. At 1706, a separator is disposed on at least a portion ofthe surface of the shield. As described above, the separator can reduceelectromagnetic noise experienced by the antenna cable emitted from theshield by providing a distance gap between the antenna cable and theshield.

The foregoing description, for purposes of explanation, used specificnomenclature to provide a thorough understanding of the describedembodiments. However, it will be apparent to one skilled in the art thatthe specific details are not required in order to practice the describedembodiments. Thus, the foregoing descriptions of specific embodimentsare presented for purposes of illustration and description. They are notintended to be exhaustive or to limit the described embodiments to theprecise forms disclosed. It will be apparent to one of ordinary skill inthe art that many modifications and variations are possible in view ofthe above teachings.

What is claimed is:
 1. A method of assembling a printed circuit board ina portable computing device, the method comprising: receiving a printedcircuit board, the printed circuit board having a base which has aplurality of attachment features for attaching a plurality of componentsto the base, wherein the base has a cut out having the size and shape toaccept a part therein, wherein the base has a mechanically weak regionwhich can experience mechanical strain during handling when the cut outis empty, wherein the mechanically weak region has reduced dimensionsrelative to other portions of the base; forming a printed circuit boardassembly by mounting a bracket in the cut out, the bracket having a sizeand shape corresponding to the cut out, wherein the mechanically weakregion experiences less mechanical strain when the bracket is positionedin the cut out and attached to the base compared to when the cut out isempty; assembling the printed circuit board assembly in the portablecomputing device; removing the bracket from the cut out of the printedcircuit board; and mounting the part in the cut out of the printedcircuit board.
 2. The method as recited in claim 1, further comprising,prior to assembling the printed circuit board assembly in the portablecomputing device, mounting the plurality of components on the printedcircuit board.
 3. The method as recited in claim 1, further comprising,after removing the bracket, forming a second printed circuit boardassembly by mounting the bracket in a second cut out of a second printedcircuit board, wherein the a second printed circuit board has a secondbase having a second mechanically weak region which can experiencemechanical strain during handling when the second cut out is empty. 4.The method of claim 1, wherein the printed circuit board is part of amain logic board of the portable computing device.
 5. The method ofclaim 1, wherein the part is a fan for cooling the portable computingdevice.
 6. The method of claim 1, wherein the bracket is comprised of asheet metal material.
 7. The method of claim 1, wherein the printedcircuit board is comprised of a resinous material.
 8. The method ofclaim 1 wherein the bracket has at least one bent portion that protrudessubstantially perpendicular from a planar surface of the bracket.
 9. Themethod of claim 8 wherein the at least one bent portion aligns theprinted circuit board within the portable computing device.
 10. Themethod of claim 1 wherein the bracket is mounted in the cut out with oneor more fasteners that are secured within one or more openings withinthe printed circuit board.
 11. The method of claim 10 wherein the one ormore openings within the printed circuit board are also used to mountthe part in the cut out.
 12. A method of assembling a printed circuitboard in a portable computing device, the method comprising: receiving aprinted circuit board, the printed circuit board having a cut out sizedto accommodate a fan component; receiving a bracket having geometrysimilar to the fan component and attaching the bracket to the printedcircuit board; assembling the printed circuit board assembly in theportable computing device; removing the bracket from the cut out of theprinted circuit board; and mounting the fan component in the cut out ofthe printed circuit board.
 13. The method of claim 12 wherein thebracket has at least one bent portion that protrudes substantiallyperpendicular from a surface of the bracket.
 14. The method of claim 13wherein the at least one bent portion aligns the printed circuit boardwithin the portable computing device.
 15. The method of claim 12,further comprising, prior to assembling the printed circuit boardassembly in the portable computing device, mounting a plurality ofcomponents on the printed circuit board.
 16. The method of claim 12,further comprising, after removing the bracket, forming a second printedcircuit board assembly by mounting the bracket in a second cut out of asecond printed circuit board.
 17. The method of claim 12, wherein theprinted circuit board is part of a main logic board of the portablecomputing device.
 18. The method of claim 12, wherein the fan is used tocool the portable computing device.
 19. The method of claim 12, whereinthe bracket is comprised of a sheet metal material.
 20. The method ofclaim 12, wherein the printed circuit board is comprised of a resinousmaterial.
 21. The method of claim 12 wherein the bracket is mounted inthe cut out with one or more fasteners that are secured to one or moreopenings within the printed circuit board.
 22. The method of claim 12wherein the one or more openings within the printed circuit board arealso used to mount the part in the cut out.